Describe single-replacement and double-replacement reactions.
5 Answers | Add Yours
A single placement reaction occurs when two elements are combined creating an oxidation reduction type of reaction. It is also called a single displacement reaction. In the process an ionic compound reacts with a free element to create a different ionic compound.
- d + ce ® c + de
- (element d is the ionic compound)
- (c is the positively charged ions)
- (e is the negatively charged ions)
- It is called a single replacement because it looks like d is replacing c
In a Double Placement Reaction occurs when two ionic compounds are mixed together. The ionic compounds split apart separating their anions and cations. A checmical reaction occurs resulting in a product that can ot be reversed/separated.
When a single replacement reaction takes place, the element that is separate to the compound would combine with the opposite element of the compound that its getting added to.
AX + Y = AY +X
On the reactant side, y is the opposite of x. Let's suppose that the equation is
2Ag + CuSO4 = Ag2SO4 +CU
Ag has a positive charge because it is a metal
SO4 is a negative ion, it's sulfate. They combine because they are opposite and combine to make a compound. Cu becomes separate.
Double replacement based on the same concept. Except that the reactant has two compounds instead of one. The same concept applies, the positive element combines with the negative element on the seocnd compound. And the negative compound combines with the positive of the second.
2NaI + CaCL2 = 2NaCl + CaI
Na (positive) would combine with cl (the negative element in CaCL2)
I (negative) would combine with Ca (positive)
A + BX ---> B + AX
Element, compound, element, compound
AX + BY ---> BX + AY
Compound, Compound, Compound, Compound
H + XI ---> I + XH
XI + BK ---> BI + XK
Join to answer this question
Join a community of thousands of dedicated teachers and students.Join eNotes